Biomedical subjects

Jacques Chiras

Publications and source records attributed to Jacques Chiras.

21 records · Page 2Linked to original sources

PubMedDate not supplied

In vitro polyvinylformaldehyde particle compatibility with chemotherapeutic drugs used for chemoembolization therapy.

PURPOSE: Because the effects of pirarubicin and carboplatin on the physical structure of particles made from polyvinylformaldehyde are not well known, we describe an experiment to test the in vitro polyvinylformaldehyde particle compatibility with these drugs used for chemoembolization of bone metastases. MATERIALS AND METHODS: Polyvinylformaldehyde particles (Ultra-Drivalon) were mixed in vitro with either pirarubicin or carboplatin as experimental samples, and with distilled water as control samples, and left for 24 h at 37 degrees C. The particles used measured 150-250 microm and 600-1000 microm in diameter. Particle morphology, including appearance, overall shape, and surface characteristics were examined using a microscope equipped with a videocamera. Particle size was measured by granulometry. Qualitative and quantitative variables were analyzed using, respectively, the two-sided Fisher's exact test and the Wilcoxon signed rank test for paired values, with a significance level of 0.05. RESULTS: No broken particles or microscopic degradations in the appearance, overall shape, or surface characteristics of any particles were observed. The particle size distribution was not significantly different between the experimental samples containing pirarubicin or carboplatin and the control sample of particles with diameters in the same range. CONCLUSION: Particles made from polyvinylformaldehyde can be mixed with pirarubicin or carboplatin without any risk of damaging their physical properties.

Antineoplastic Agents↗

PubMedDate not supplied

T1 signal hyperintensity in the sellar region: spectrum of findings.

T1 signal hyperintensity is a common finding at magnetic resonance imaging of the sellar region. However, this signal intensity pattern has different sources, and its significance depends on the clinical context. Normal variations in sellar T1 signal hyperintensity are related to vasopressin storage in the neurohypophysis, the presence of bone marrow in normal and variant anatomic structures, hyperactive hormone secretion in the anterior pituitary lobe (eg, in newborns and pregnant or lactating women), and flow artifacts and magnetic susceptibility effects. Pathologic variations in T1 signal hyperintensity may be related to clotting of blood (in hemorrhagic pituitary adenoma, pituitary apoplexy, Sheehan syndrome, or thrombosed aneurysm) or the presence of a high concentration of protein (Rathke cleft cyst, craniopharyngioma, or mucocele), fat (lipoma, dermoid cyst, lipomatous meningioma), calcification (craniopharyngioma, chondroma, chordoma), or a paramagnetic substance (manganese, melanin). After treatment, T1 signal hyperintensity may result from the presence of materials used for surgical packing (gelatin sponge, fat); from compression of the cavernous sinus and reduction of the venous flow, caused by overpacking of the operative bed; or from hormone hypersecretion by a remnant of normal tissue in the anterior lobe of the pituitary gland.

Adolescent↗

PubMedDate not supplied

Intra-arterial nimodipine for the treatment of symptomatic cerebral vasospasm after aneurysmal subarachnoid hemorrhage: preliminary results.

BACKGROUND AND PURPOSE: Cerebral vasospasm remains a major problem in patients recovering from aneurysmal subarachnoid hemorrhage despite advances in medical, surgical, and endovascular care. Our purpose was to assess the efficacy of intra-arterial nimodipine, a calcium-channel blocker acting mainly on cerebral vessels, in preventing delayed neurologic deficits in patients with symptomatic vasospasm. METHODS: Clinical charts of 25 consecutively treated patients were retrospectively reviewed. A multifactorial decision tree was used to determine the indication for angiography and subsequent endovascular treatment. Nimodipine was infused intra-arterially via a diagnostic catheter in the internal carotid artery or vertebral artery at a rate of 0.1 mg/min. Angiographic vasospasm before endovascular treatment, immediate vessel caliber modifications, and short- and long-term clinical efficacy of the procedure were assessed. RESULTS: Thirty procedures were performed in 25 patients. Clinical improvement was observed in 19 (76%), 16 of whom improved after the first endovascular procedure, two after the second intra-arterial treatment, and one after the third. Of these 19 patients, only 12 (63%) had notable vascular dilatation at postprocedural angiography. Dilatation of infused vessels occurred in only 13 (43%) of 30 procedures. After follow-up of 3-6 months, 18 (72%) of 25 patients had a favorable outcome (Glasgow outcome scale score of 1-2 and modified Rankin scale score of 0-2). No complications were observed. CONCLUSION: Intra-arterial nimodipine is effective and safe for the treatment of symptomatic vasospasm after subarachnoid hemorrhage. Further prospective randomized studies of cerebral blood flow are needed to confirm these results.

Adult↗